Question

If speed of a motor car becomes six times, then the kinetic energy becomes

• A. $6times$
• B. $36times$
• C. $12times$
• D. none of these

Answer 1

Answer: (B)

$36times$

The kinetic energy of the boat is given by:

$KE=\frac{1}{2}m{v}^2$

Now when the speed becomes six times the initial speed:

$K{E}^{\prime }=\frac{1}{2}m(6v{)}^2$

$K{E}^{\prime }=36\times \frac{1}{2}m{v}^2$

$K{E}^{\prime }=36\times KE$